Method of making sign panels



Jan. 11, 1944. v, vU s METHOD OF MAKING SIGN PANELS Filed May 21, 1940 Patented Jan. 11, 1944 IVIETHOD OF MAKING SIGN PANELS Vaclav Viirbs, Krhova-Hradky,

Bohemia-Moravia; vested in the Alien Property Custodian Application May 21, 1940, Serial No; 336,461 In Bohemia-Moravia May 25, 1939 Claims.

This invention relates to sign-panels of the type having light-reflecting areas provided thereon, as for instance warning or orientation sign-panels, way indicators and the like, such as are used alongside of roads to mark railway or road crossings, serpentine road sections and the like. Heretofore sign-panels of this type have been made by a method in which the light-refleeting layers in the form of signs or letters are caused to adhere to the lacquer coated face of the panel before the lacquer coating has time to harden and then, when this backing coating has hardened, the whole of the panel together with the reflecting layer is provided with a transparent covering layer of paint for protection against atmospheric agents. The object of the invention is to secure, by a particular method of manufacturing sign-panels of the above described type, a perfect adhesion of the lacquer layers as well as of the light-reflecting areas and of the paint coating on the same, a permanent reflection effect and a resistance as great as possible against atmospheric influences. According to the invention these desired results are obtained by the use as a light reflecting surface of finely corrugated metal foil, preferably an aluminium foil. The expression finely corrugated foil is used in the body of the specification and in the claims to describe particularly an irregularly wrinkled flat foil whose folds, extending in all directions and considerably varying in length, form waves which on their sides reflect light in all directions. By corrugating the metal foil perfect reflection of light in all directions is obtained and moreover intimate union of the foil with the lacquer backing and the covering coating is secured. Advantageously the foil is provided with fine fissures or perforations preferably after it has been secured to the backing lacquer layer. Thus evaporation of the lacquer solvent is permitted during the hardening of the backing layer also within the areas under the applied foil and the formation of bubbles and bumps on the face of the metal foil is prevented, and moreover the aforementioned fissures or perforations insure a strong bond between the covering and backing lacquer layers, thereby increasing the strength and durability of the sign-panel.

The invention will now be described in greater particularity and with reference to the accompanying drawing, whose several figures diagrammatically illustrate a mode of operation in the practical working of the method according to the invention; in the drawing Fig. 1 is a section of a panel provided with a lacquer backing coat; shown are a plain metal foil, and a corrugated foil, before application to the panel surface;

Fig. 2 is a similar section showing application of a metal foil, by the margins thereof to the panel;

Fig. 3 is a similar section through the finished sign panel, the same being a section on line IIIIII of Fig. 6;

Fig. 4 is a section on line IV-IV of Fig. '7;

Fig. 5 is a view illustrating a panel after securing thereon a corrugated metal foil in the manner indicated in Fig. 2;

Fig. 6 is view showing a finished sign panel with reflecting sign and opaque surrounding area; and

Fig. 7 is a view showing a modification of the combination illustrated in Fig. 6.

As metal foils there is made use of very thin aluminium, tin or other metal foils which are first finely corrugated or wrinkled in such a manner as to have the appearance of a crumpled leaf which, however, is substantially flat. A1- ternatively it is possible to cut out the metal foil to a larger size than that of the surface to be covered by the same and then cause the foil to adhere by its margins on the still sticky surface to be covered in such a way that the portion of the foil between such margins becomes arcuate, thereafter pressing the foil against the lacquer backing, for instance, by means of a rubber roller, whereby the whole inner surface of the metal foil becomes corrugated, the corrugations extending in all directions (see Fig. 4) without projecting above the plane of the foil so that the finished sign-panel is perfectly smooth.

In the practical working of the method according to the invention the panel to be treated, e. g. a sheet of metal, is cleaned, if desired by sand blasting, so as to insure reliable adhesion of the lacquer coating on the surface of the panel. The lacquer backing is formed preferably with a synthetic resin lacquer. Preferably a lacquer is used which must be heated to a certain temperature in order to harden, e. g. a synthetic resin lacquer which does not change its colour at a temperature of between about C. and C. This lacquer is applied on the panel, e. g. by spraying, and then the panel is caused to dry, preferably by heating to a comparatively low temperature, e. g. to 60 C. during a period of ten minutes. After such heating the lacquer coating is still sumciently sticky. The sign, letter or the like, which is cut out from an aluminium, tin or other metal foil, 3 or 3 is then applied on this coating and adheres to the same. The signs or letters are out about one third larger in size than their desired size on the panel. Before its application (3', Fig. l) or during such application (3, Fig. 2), the foil is so corrugated as to reduce the design to the required size, so that when the foil is forced down completely on the lacquer backing, e. g. by means of a rubber roller, fine protuberances Ml, Fig. 5) are formed on the surface of the foil and the latter is completely pressed down flush with the plane of the panel. In this way irregular protuberances and wrinkles extending in all directions arise in the foil, such protuberances and wrinkles reflecting the light in all directions. The stuck-on foil is provided with fine fissures which are obtained either by interrupting the crests of the corrugations at certain points, or by perforation by means of a metallic brush or the like, as indicated in the upper right corner of Fig. 5. Then the panels are placed in a furnace heated to about 120-140 C. where they are left for a comparatively long period, e. g. 1-2 hours. By this burning the backing lacquer hardens on the panels. After removal from the furnace and cooling down the panels are provided with an opaque covering paint which covers, the edges of the foil and delimits the reflecting foil areas exactly to the desired shape (Fig, 6). The opaque covering lacquer also prevents the edges, 1, of the foils from becoming loosened and fringed. After application of the covering paint, which may be black, blue or of any colour, the panels are allowed to dry somewhat and then are again burnt in a furnace at a temperature of about 120 to 140 C. After removal from the furnace and cooling the panels are provided, e. g. by spraying, with a protective layer, 9, of a colourless lacquer of the same composition as that of the backing layer, 2, e. g. a synthetic resin lacquer. Through the fissures of the foils this lacquer layer becomes intimately united with the backing lacquer layer, 2, so that it cannot be loosened by the atmospheric agents. When the insulating lacquer has been sprayed on the panels the latter are once more allowed to dry somewhat and then are subjected to drying in a furnace at a comparatively low temperature, e. g. 80 C. for about half an hour, whereafter the panels are left to dry completely at room temperature.

The described method also permits to provide reflecting areas on panels on which it is then possible to paint the desired signs, letters or the like by means of opaque lacquers (see Figs. 4 and '1) Before the application of the final protective layer the foil may be provided with a transparent coloured lacquer layer, e. g. a yellow layer, so that the metal foil will have a golden aspect.

Most advantageously an aluminium foil is used in carrying out the improved method, as such foil insures to the highest degree constant lightrefiecting characteristics even after a prolonged exposure to the atmospheric agents.

What I claim is:

1. Method of making a sign panel having a light-reflecting area thereon, which comprises coating a surface of a panel with a backing layer of a lacquer comprising a heat-hardenable resin,

elf)

partially drying the backing layer to a tacky state, causing a sheet of thin bright metal foil to adhere to the panel by pressing the former against the tacky backing layer of the latter the metal foil being provided with fine corrugations over the full area, hardening the backing layer whereby to secure the finely corrugated metal foil to the panel and finally providing the so-treated panel surface with a transparent protective coatin-g layer.

2. Method of making a sign panel having a light-reflecting area thereon, which comprises coating a surface of a panel with a backing layer of a lacquer comprising a heat-hardenable resin, partially drying the backing layer to a tacky state, causing a sheet of thin bright metal foil to adhere to the panel by pressing the former against the tacky backing layer of the latter the metal foil being provided with fine corrugations over the full area, piercing the adhesively secured finely corrugated foil so as to provide a plurality of fine fissures or perforations therethrough, hardening the backing layer whereby to secure the finely corrugated metal foil to the panel and finally providing the so-treated panel surface with a transparent protective coating layer.

3. Method of making a sign panel having a light-reflecting area thereon, which comprises coating a surface of a panel with a backing layer of a lacquer comprising a heat-hardenable resin, partially drying the backing layer to a tacky state, causing a sheet of thin bright metal foil to adhere to the panel by pressing the former against the tacky backing layer of the latter the metal foil being provided with fine corrugations over the full area, piercing the adhesively secured finely corrugated foil so as to provide a plurality of fine fissures or perforations therethrough, hardening'the backing layer whereby to secure the finely corrugated metal foil to the panel, applying to areas of the panel surface not intended to be reflective an opaque coating which covers margins of the foil and outlines a desired indicium on said panel surface and finallyproviding the so-treated panel surface with a transparent protective coating layer.

4. The method defined by claim 1, wherein the metal foil is so applied to the tacky backing layer that at first it is secured only at its margins While the main portion of the foil between the margins is arcuate, whereupon the foil is so pressed throughout its full area into engagement with the tacky backing layer that a plurality of fine corrugations are developed irregularly over the area of the foil.

5. A sign panel comprising, in combination, a sheet metal panel, a sheet of finely corrugated, irregularly wrinkled, bright metal foil covering said sheet metal panel and secured thereto by a baked-0n intermediate layer of lacquer comprising a heat-hardened resin, over portion of said foil a layer of an opaque coating composition there being light-reflective areas of exposedfine- 1y corrugated bright metal foil and relatively non-reflective areas of opaque coating composition, said areas cooperating to define a desired indicium, and an outer overall protective layer of a transparent coating composition.

vAoLAv viiRBs. 

